England's hottest weather in more than three centuries is making Graham Birch, the country's best natural-resources fund manager for a decade, concerned about the state of his spring crop.

The corn and grasses grown for livestock on the 2,300-acre farm in the southwestern county of Dorset are already beset by the heat and lack of water, Birch said by phone on May 18. Rain will be needed soon to keep yields for wheat and rapeseed planted at the end of last year from dropping, he said.

European farmers are contending with the driest growing conditions in more than three decades. The European Union warned this week that soil moisture is now "critical" in at least six countries after some places had their driest March on record. France's soft-wheat crop, the EU's largest, will drop 12 percent, and German output will slide 7.2 percent, local forecasters said May 18.

"It's the spring crops I'm worried about because that's what's seeing some severe drought stress," said Birch. "It'd be nice to have some rain in the next couple of weeks."

Birch started a sabbatical from BlackRock Inc. (BLK), the world's biggest money manager, in 2009 and formally left in 2010, when the team was managing $36.3 billion of assets. His BlackRock Gold and General Fund was the top performer among 858 U.K.- domiciled mutual funds over a decade, averaging gains of almost 23 percent a year, data from Morningstar Inc. (MORN) show.

David Fuller's view Many veteran subscribers will have fond memories of Graham Birch's era at BlackRock, having profited from his fund for many years. I eventually sold my position too soon, in late July 2010, but many of you probably still hold it.

Despite his comments, Birch is likely to feel that it is easier to make money in the markets than the worthy challenge of farming, which is hard work and highly speculative. The farmer sows without knowing if the seed will germinate, as we see in today's drought conditions. A growing crop will remain susceptible to adverse weather conditions, pests or disease, so the farmer is uncertain as to what will be left when the crop is harvested. Even with a successful harvest the vagaries of the market can work against the most diligent farmer.

In an underdeveloped country such as India, crops can rot in the field due to distribution problems and the lack of refrigeration. Sometimes everything works out for the farmer but too often it is extremely hard work for uncertain reward.